Monorepos & Workspaces

Workspaces are handled out-of-the-box by Knip.

Workspaces are sometimes also referred to as package-based monorepos, or as packages in a monorepo. Knip uses the term workspace exclusively to indicate a directory that has a package.json.

Configuration

Here’s example configuration with custom entry and project patterns:

knip.json

{
  "workspaces": {
    ".": {
      "entry": "scripts/*.js",
      "project": "scripts/**/*.js"
    },
    "packages/*": {
      "entry": "{index,cli}.ts",
      "project": "**/*.ts"
    },
    "packages/cli": {
      "entry": "bin/cli.js"
    }
  }
}

Tip

Run Knip without any configuration to see if and where custom entry and/or project files are necessary per workspace.

Each workspace has the same default configuration.

The root workspace is named "." under workspaces (like in the example above).

Caution

In a project with workspaces, the entry and project options at the root level are ignored. Use the workspace named "." for those (like in the example above).

Workspaces

Knip reads workspaces from four possible locations:

1. The workspaces array in package.json (npm, Bun, Yarn, Lerna)
2. The packages array in pnpm-workspace.yaml (pnpm)
3. The workspaces.packages array in package.json (legacy)
4. The workspaces object in Knip configuration

The workspaces in Knip configuration (4) not already defined in the root package.json or pnpm-workspace.yaml (1, 2, 3) are added to the analysis.

Caution

A workspace must have a package.json file.

For projects with only a root package.json, please see integrated monorepos.

Additional workspaces

If a workspaces is not configured as such in package.json#workspaces (or pnpm-workspace.yaml) it can be added to the Knip configuration manually. Add their path to the workspaces configuration object the same way as "packages/cli": {} in the example above.

Source mapping

Let’s say we have this module in a monorepo that imports helper from another workspace in the same monorepo:

index.js

import { helper } from '@org/shared';

The target workspace @org/shared has this package.json:

package.json

{
  "name": "@org/shared",
  "main": "dist/index.js"
}

The module resolver will resolve @org/shared to dist/index.js. That file is usually compiled and git-ignored, while Knip wants the source file instead. If the target workspace has a tsconfig.json file with an outDir option, Knip will try to map the “dist” file to the “src” file:

tsconfig.json

{
  "compilerOptions": {
    "baseUrl": "src",
    "outDir": "dist"
  }
}

If src/index.ts exists, Knip will use that file instead of dist/index.js. Currently this only works based on tsconfig.json, in the future more source mappings may be added.

Additional options

The following options are available inside workspace configurations:

• ignore
• ignoreBinaries
• ignoreDependencies
• ignoreMembers
• includeEntryExports

Plugins can be configured separately per workspace.

Use --debug for verbose output and see the workspaces Knip includes, their configurations, enabled plugins, glob options and resolved files.

Lint a single workspace

Use the --workspace (or -W) argument to focus on a single workspace (and let Knip run faster). Example:

knip --workspace packages/my-lib

This will include the target workspace, but also ancestor and dependent workspaces. For two reasons:

• Ancestor workspaces may list dependencies in package.json the linted workspace uses.
• Dependent workspaces may reference exports from the linted workspace.

To lint the workspace in isolation, there are two options:

• Combine the workspace argument with strict production mode.
• Run Knip from inside the workspace directory.